In certain applications it is necessary to limit the range of variation of the output voltage of an amplifier, and even to neutralise its output by bringing it to an arbitrary potential, for certain ranges of variations of its input signal. This is true particularly when it is desired to reduce or level the components of a signal whose amplitude lies within a certain range without affecting any other components. This situation may be encountered in various circumstances, and particularly when it is wished to avoid acting on a signal which, by its amplitude, indicates a malfunction of the circuit which generated it.
The present invention is intended to limit the output voltage of an amplifier and even to neutralise its output for certain ranges of variation in its input voltage.